Telephone system



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TELEPHONE SYSTEM.

APPLICATION FILED JULY 26, 19H.

Patented Aug. 9, 1921,

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1'0 all whom it may concern.

UNITED STATES. PATENT OFFICE- cHARLns L. GOODRUM, on NEW YORK, AND HENRY .P. CLAUSEN, ormonn'r ERNO NEW YORK, :AssIGNoRs TO WESTERN ELECTRIC COMPANY, mooRroRATEn'oF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Be it known that we, CHARLES L. GooDRUM and HENRY P. CLAUsnN, citizens of the United States residing at New York, in the county of New York and State of New York and at Mount Vernon, in the county of Westchester and State of New York, respectively, have invented certain new and useful .Im-

provements in Telephone Systems, of which the following is a full, clear, concise, andv exact description.

This invention relates to telephone systems, and more particularly to the trunking arrangements employed in such systems.

In telephone systems it is particularly desirable that the apparatus and trunk lines employed in such systems may be common to a plurality of exchanges, since by this arrangement the amount of necessary equipment is thereby greatly reduced. L

This arrangement is particularly advantageous for use in systems of relatively great size which systems may be composed of zones or districts, which in turn are composed of a plurality of exchanges. The various exchanges of the system are frequently widely separated, necessitating trunk lines of great length. In order to minimize the number of trunks employed between the various divisions and subdivisions of such a system it is proposed, in accordance with this inven tion, to render the trunk lines extending from one zone to another common to two or more exchanges, at the same time retaining the numerical designation of each group of trunk lines.

The drawing diagrammatically represents a portion of a telephone system employing the present invention. The portion of the drawing at the left of the broken line represents a non-numerical switch and a first selector switch located in an exchange of one zone, while that portion of the drawing diagrammatically indicated at the right of the dotted line represents the apparatus and equipment located in a second zone. The dotted line rectangles designated by refer ence character X represent telephone exchanges in the last mentioned zone.

. 1n the course of the description reference vill be made to a line switch. It will be understood, however, that any form of nonnumerical switch may be used for this pur- Application filed July 26,

1917. Serial .No'. 182, 963.

pose,but a switch of the type disclosed in patent to 1&e1th No. 1,151,543, August 24, 1915, has been shown in the present disclosure.

It is believed that the invention-is best explained by describing the establishment of a and a called substation B. I

WVhenajcalling subscriber at A removes his receiver from its switchhook, brushes 1, 2 and 3 of a finder switch are operated'in the well-known manner to locate the terminals 4, 5 and 6 of the calling line. It will be understood, however, that any form of nonnumerical'switches may be employed instead of the finder switchherein mentioned.

As soon as the terminals of the calling line have been seized, the line relay 7 of a first seconnection between a calling substation A lector switchv is energized over a .circuit,

which may betraced from ground, left-hand winding ofrelay -7,side-switch wiper 8 in its first position, finder brush 2, terminal 5, substation apparatus A, terminal 4, finder brush 1, side-switch wiper 9 in its first posifront contact of the relay 7, winding of the relay 10 to grounded battery. The relay 10 attracts its armature and when the subscriber operates his sending device 11 to transmitimpulses corresponding'to the first digit of the desired number, the line relay 7 vibratesits armature and at its back contact closes the circuit from ground, armature and front contact of relay 10, winding of the relay 12, to grounded battery. The relay 12 attracts its armature to close a circuit for the escape magnet '13 from grounded battery, winding of magnet lS, side-switch wiper 14 in its first position, armature and contact of slow-releasing. relay 12 to ground.-

. In response to the vibrations of the armature of the relay 7,-the primary motor magnet 15 is operated over a circuit extending from grounded battery, winding of the mag net 15, front contact and armature of the relay 10, back contact and armature of the relay 7, to ground. The primary motormagnet 15 attracts "its armature for each impulse transmitted and elevates the brush shaft 16 Patented Aug. 9, 1921.

of the selector switch to position. brushes 17, 18 and 19 into operative relation with the particular row in which trunk lines from,

the desired zones terminate. At the close of the first series of impulses, the line relay 7 attracts its armature for such a long interval that the relay 12 deenergizes to interrupt the operating circuit of the escape magnet 13 and cause this magnet to move the sideswitch wipers into their second position.

With the side-switch wipers in their second position, the relay 31 is energized to cause the energization of slow releasing relay 32 and to cooperate in applying current of proper character for selecting the desired exchange as will more fully appear in the course of this description. In the second position of the side-switch wipers, the secondary or rotary movement of the" swltch is also brought about by the secondary motor magnet 20. The secondary movement takes place under the control of the escape magnet, which is initially energized over a circuit completed from grounded battery, winding of the escape magnet 13, side-- switch wiper 14 in its second position, sideswitch wiper 76 in its second position, secondary off-normal contact 75, which is closed until the switch shaft is rotated, to ground. If the first trunk of the selected group is busy, the escape magnet is then maintained energized over a circuit traceable from grounded battery, winding of escape magnet 13, side-switch wiper 14 in its second position, conductor 22, test brush 17, test terminals, similar to terminals 28, to ground at the left-hand front contact and armature of relays similar to relay 23. With the sideswitch wipers in their second position, the secondary motor magnet 20 operates over a circuit extending from grounded battery, winding of magnet 20, its armature and contact, side-switch wiper 21 in its second position, front contact and armature of relay 7, to ground. The secondary motor magnet 20 interrupts its own circuit to rotate the brush shaft 16 through its rotary movement. If the first trunk of theselected group is idle, this condition will be indicated by the absence of ground on its test terminal, and since the initial energizing circuit of the escape magnet 13 is open at the secondary off-normal contact when the brush shaft has taken its first rotary step, the escape magnet 13 deenergizes to move the side-switch wipers into theinthird position. This interrupts the stepping circuit of the secondary motor magnet at the side-switch wiper 21. If the first trunk of the selected group is busy, this condition will be indicated by the presence of ground on the test terminal, in which case the escape magnet 13 is energized over the test circuit previously described. When, however, the test brush 17 engages the test terminal of an idle line, which is characterized by the absence of ground, the escape magnet deenerglzes to move the side-switch wipers into their third position. When the sideswitch wipers leave their second position, the operating circuit of the secondary motor magnet 20 is interrupted at the side-switch wiper 21.

lIt should here be noted that the selector switch employed is provided with an additional brush 24 mounted on the brushshaft 16 to be elevated therewith. The brush 24 is rotatably mounted on the brush shaft, and is held in the same radial position in engagement with the terminals 26 and 27, by means of the fixed bar 25.

Let it be assumed that the brush shaft was elevated one step or to the first level of the switch, and that the brush shaft was rotated until the brushes 17, 18 and 19 engaged the terminals 28, 29 and 30. In this case, the brush 24 will then be in engagement with the terminal 26, which is connected to positive battery. Positive battery will then be applied to the terminal 29 over a clrcuit traceable from grounded battery, terminal 26, brush 24, outer armature and back contact of relay 31, which released when switch arm '70 left position 2, armature and front contact of slow-releasing re- "lay 32, switchbrush 18, terminal 29, conductor 33, winding of polarized'relays 34 and 35 to ground at the left-hand back contact and armature of relay 23."

The relay is energized in this circuit and completes a circuitfor energizing the slow releasing relay 36, which circuit is traceable from grounded battery, winding of the relay 36, front contact and armature of the polarized contact 35, to ground. Relay 36 attracts its armature and completes a circuit from ground, through. the righthand winding of the plunger operating magnet 37 to grounded battery. The magnet 37 is energized and attracts its armature, causing the plunger 38 to. close the contacts of the various springs individual to the trunk seized. As soon as the plunger 38, is operated relay 39 is energized over a circuit traced from grounded battery, left-hand wlndlng of relay 39, left-hand winding of the repeating coil 40, contact 41 and its spring, conductor 42, trunk terminal 30, selector brush 19, through the side-switch wiper 9 in its third position, finder brush 1, terminal 4, substation apparatus A, terminal 5, finder brush 2, side-switch wiper 8, back contact and armature of relay 32, selector brush 18, trunk terminal 29, conductor 43, contact 44 and its spring, conductor 45, left-handwindingof repeating coil 46, righthand winding ofrelay 39to ground. The

relay 39 attracts itsarmatures and at its left-hand armature and front contact comrelay 37 holds the plunger 38 actuated dur-.

ing the conversation. At the armature and contact of relay 47 a circuit is also completed from ground through contact 48, winding of relay 23, to grounded battery, to energize this relay, which in turn maintains a busy potential on the'trunk line which has been seized. At the right-hand armature and contact of relay 39 the impulses from the calling dial 11 are repeated to operate a series of numerical switches, one of which has been indicated by thebrushes 51 and 52. These numerical switches which may be of any well-known type operate to complete the connection through to the called subscribers substation at B. p I

When the calling subscriber replaces his receiver on the switchhook, the relay 39 deenergizes to retract its armatures. At its left-hand armature and contact the energiz-,

ing circuit of relay'47 is interrupted, causr ing this relay to retract its armature. The holding circuit of relay 37, which was completed through the armature and contact of relay 47,is interrupted and permits the plunger 38 to be withdrawn. Also the energizing circuit of the relay 23, which circuit extended through contact 49 and through the contact and armature of relay 47, is opened and ermits relay 23 to retract its armatures.

round is thereupon removed from test terminal 28 and the relay '59 which was energized over a circuit traceable from grounded battery, winding of relay 59, side-switch wiper 60 in its third position, conductor 22,

test brush 17, test terminal 28, to ground, at the left-hand front contact and armature of relay 23-, retracts its armature to complete an energizing circuit for the release magnet 55. This circuit is traceable from grounded battery, winding of release magnet 55, offnormal contact 56, which was closed upon the first vertical step of the brush shaft 16, side-switch wiper 61 in its third position, back contact and armature of relay 59, to ground. Magnet 55 attracts its armature to withdraw the vertical pawl 57 and the rotary pawl 58 fromtheir respective ratchet teeth to permit the brush shaft 16 of the first selector to be restored.

If the calling subscriber had abandoned the call before the side-switch wipers had moved into their third position, the energiz ing circuit for the release magnet would have been completed from grounded-battery," winding of release magnet 55, oil-normal contact 56, side-switch wiper 61 in its first and second positions, armatures and back contacts of relays 10 and 7, to ground.

Let it be assumed that the subscriber at substation A operates his dial to place the brushes 17, 18 and 19 into operative relation with the trunk terminals 65, 66 and 67 of r i the second group of trunks terminating in the switch. Under this assumption the brush 24 of the switch will be placed in engagement with the terminal 27 to apply negative battery to the selected trunk line, with the result that the polarized relay 34 is energized.v Relay 34, in operating, energizes a relay at the exchange X similar to the relay '36, with the resultthat a line switch at the exchangek seizes the trunk indicated by the conductors 42 and 43. In like manner,

, of this selector had been elevated to select one of the fourth group of trunks, the polarized relay 69 would have been actuated to select the exchange X In this disclosure polarized relays have been employed to eflect the selection of the proper exchange, but it willbe understood that any electromagnetic'means which may be variably controlled from a distant point, can be used.

lVhat is claimed is:

1. In a telephone system, an incoming line, an outgoing line, a plurality of ex- (hanges in which said outgoing line terminates, aplurality of electromagnetic devices eonnected to saidoutgoing line, one of said electromagnetic devices being individual to each exchange, mechanism for interconnecting said lines, and mechanism operative at said interconnecting means for selectively operating said electromagnetic devices to select a desired exchange.

2. In a telephone system, an incoming line, an outgoing line, means for interconnecting said lines, a plurality of exchanges in which said outgoing llne terminates, and a plurality of electromagnetic devices associated with. said outgoing line and equal to incoming line with an idle line of a selected group of outgoing lines, means controlled by said automatic switch for sending impulses of different characteristics, and means responsive to an impulse of a certain characteristic for controlling the extension of said outgoing line to one of said exchanges.

4. In a telephone system, an incoming line,

groups of outgoing lines, each of said outgoing lines terminating 1n a plurallty of exchanges, an automatic switch connecting, said incomlng line to any of said outgoing lines, electromagnetic devices responsive to said devices for extending a selected out going line to one of said exchanges.

5. In a telephone exchange system, a plurality of exchanges, an incoming line, groups oit outgoing lines, each of said outgoing lines terminating in a plurality of exchanges, an-

automatic switch for interconnecting said inrson'iing line with an idle line oi a selected,

vsively movable switch controlled by a callgroup of outgoing lines, means for sending impulses of different characteristics and means selected by said switch in seizing an outgoing line of a desired group and responsive to an impulse of one character for controlling the extension of said outgoing line to one of said exchanges.

6. In a telephone system, an incoming line, an outgoing line, a plurality of stations in which said outgoing line terminates, an automatic switch for-interconnecting said incoming and said outgoing lines, means for transmitting impulses of different polarity, means operated in response to the setting of said automatic switch and the transmission of an impulse of a certain polarity for selecting one of said stations, and means for extending said outgoing line beyond said selected station. v

7. In a telephone system, a trunk line, a plurality of relays associated with said trunk line, a plurality of other trunk lines accessible to said first trunk line, means whereby the operation of each one of said relays connects said first trunk line with one of said other trunk lines, and an automatic progressively movable switch for seizing said first trunk line, and for electing which one of said relays shall be operated and for operating the elected relay.

8 In a telephone system, a trunk line,

other trunk lines normally disconnected therefrom, a, plurality of relays associated with said first trunk line, each of said relays responsive to an impulse of a different char- (acter to connect said first trunkline with which one of said relays shall be operated f and for operating-the elected relay.

9. In a telephone system, a trunk line, a plurality of other trunk lines, a plurality of relays associated with said first trunk line, each of said. relays adapted to "connect said first trunkline with a different one of said other trunk lines, and an automatic progresing subscriber for seizing said firstitrunk line and for operating any one of said relays to connectat will with any one of said other trunk lines. p

10. In a telephone system, a trunk .line comprising'a pair of conductors, a plurality of other trunk lines, means for sending impulses of different polarity over either conductor of said trunk line, and means responsive to a single impulse of a certain charactor for connecting said first trunk line with a particular one of said other trunk lines.

11. In a telephone system, a trunk line, a plurality of other lines, a switch for each one of said other lines, a plurality of terminals for said trunk line, means associated with said terminals whereby "when one terminal is seizel, one of said switchesis operated to extend the trunk to one particular one of said other lines, and whereby. when a difierent terminal is seized, another and different one of said switches is operated to extend the trunk to its corresponding line.

In witness whereof, we hereunto subscribe our names this 24th day of July A.D., 1917.

CHARLES L. GOODRUM;

HENRY P. CLAUSEN.

ing said first trunk line, and for electing I DISCLAIMER.

1,387,386.0harles L. Goodrum, New York, N. Y., and Henry P. Olausen, Mount Vernon, N. Y. TELEPHONE SYs'rEM. Patent dated August 9, 1921. Disclaimer filed March 5, 1929, by the assignee, Western Electric Company, Incorpomted.

Hereby enters this disclaimer to the said claims of said Letters Patent which are in the following words, to wit:

7. In a telephone system, a trunk line, a plurality of relays associated with said trunk line, a plurality of other trunk lines accessible to said first trunk line, means whereby the operation of each one of said relays connects said first trunk line with one of said other trunk lines, and an automatic progressively movable switch for seizing said first trunk line, and for electing which one of said relays shall be operated and for operating the elected relay.

8. In a telephone system, a trunk line, other trunk lines normally disconnected therefrom, a plurality of relays associated with said first trunk line, each of said relays responsive to an impulse of a different character to connect said first trunk line with any one of said other trunk lines, an automatic progressively movable switch for seizing said first trunk line, and for electing which one of said relays shall be operated and for operating the elected relay.

9. In a telephone system, a trunk line, a plurality of other trunk lines, a plurality of relays associated with said first trunk line, each of said relays adapted to connect said first trunk line with a different one of said other trunk lines, and an automatic progressively movable switch controlled by a calling subscriber for seizing said first trunk line and for operating any one of said relays to connect at will with any one of said other trunk lines.

11. In a telephone system, a trunk line, a plurality of other lines, a switch for each one of said other lines, a plurality of terminals for said trunk line, means associated with said terminals whereby when one terminal is seized, one of said switches is operated to extend the trunk to one particular one of said other lines, and whereby when a different terminal is seized, another and different one of said switches is operated to extend the trunk to its corresponding line.

[Ofiicial Gazette March '19, 1929.] 

